I didn't use vbseo.
This is also not working.
RewriteRule [^/]+/([\d]+)-.+-([\d]+).html showthread.php?t=$1&page=$2 [NC,L]
RewriteRule [^/]+/([\d]+)-.+.html showthread.php?t=$1 [NC,L]
When I clicked "http://example.com/threads/1234-topic-title" it redirects main domain "http://example.com".